2014年，Moke 2 发布，中国 App Store 引入1元定价，我得到了什么，学到了什么。
It is a common API design pattern. But how to do it in Swift is not well known.
iWatch, no. iBand and new iPod, yes. iBud, maybe.
How to use UIViewController actor chain on iOS 8 and how it is implemented.
Rules to follow when designing initializers.